Case report: Spontaneous ruptures of the quadriceps and triceps tendons following parathyroidectomy for secondary hyperparathyroidism

Introduction: Spontaneous tendon ruptures are a rare event. The few cases described in the literature are mostly associated with chronic metabolic diseases, such as chronic haemodialysis in patients with renal failure and subsequent secondary hyperparathyroidism.

Methods: We report the case of a 34-year-old male patient who had been on haemodialysis for five years due to renal failure caused by nephritis and nephrocalcinosis. Suffering from secondary hyperparathyroidism (serum calcium 2.54 mmol/l, parathyroid hormone 2,648pg/ml) he was referred to us for surgical therapy.

Results: As a renal transplantation was planned, we performed a subtotal parathyroidectomy with thymectomy. Despite a high-dose oral substitution of calcium and vitamin-D, calcium postoperatively dropped to 0.93 mmol/l, resulting in titanic seizures with syncopation on the fifth day after surgery. One day later, painful swellings of both knees and the right elbow were radiologically diagnosed as ruptures of the quadriceps and triceps tendons, respectively. Thereupon they were re-fixated operatively by our trauma surgeons. Continuing a high-dose oral calcium- and vitamin-D-substitution the patient could be discharged from hospital five weeks after the initial operation.

Conclusion: Spontaneous tendon ruptures might be related to osteolysis at the tendon insertion sites caused by long-lasting high levels of parathyroid hormone, and could be triggered by seizures due to hypocalcaemic states after parathyroidectomy.